ZF tranny info
Discussion
Hi all
Wanted to get this info on the net, hopefully it'll help others with the ZF 6HP26 transmission on Jags.
Also affects some Aston Martin, at least one Hyundai, and a few BMW as well.
Issue: sealed for life tranny leaks from composite sump - gasket failure. Cheap nasty fasteners made of cheese have a head size not commensurate with the tiny torx recess. They're also ordinary steel and the casting boss these things screw into are open holes. Lovely little reservoir for all that salty road water. You can guess what happens when attempt is made to remove these pathetic screws. Plain steel screws into aluminium with a dosing of salt water is not sound engineering practise.
Jaguar wanted £700 + to do the job, but much of this is the con trick price of ZF fluid.
I've done mine myself using a 4mm drill and an SKF stud extractor to get the old screws out.
Replace the screws with M6 x 30 stainless socket cap heads and washers. Also fill the top of the hole with waxoyl.
As for the fluid - don't let them BS you that your tranny will fail if anything other than ZF golden elixir is used - it's actually Mercon 5 and you can do a fill for about £30. In fact in some countries Mercon is specified for this box.
Filling presents problems since the fill point is on the side of the box with not much clearance - so no gravity filling here. I spent £12 on a small fuel rated bilge pump at a local Chandlers and it included pipes - best £12 I ever spent.
All in all I've dropped the sump, replaced the gasket, replaced the fasteners with cap head stainless which is what should have been used in the first place, and done a complete refill for about £50. Box runs perfectly.
This was a major issue a while ago with Jag and BMW owners as no one seemed to know what the alternative was for ZF ransom oil, and how to get the old screws out.
So save yourself over £600 - stud extractor, fuel rated small boat bilge pump, M6 x 30 stainless cap heads, Mercon 5 fluid - jobs a good un.
Hopefully this would help anyone with a leaking 6HP26 tranny sump who might be fooled into thinking they have to pay the ransom.
Wanted to get this info on the net, hopefully it'll help others with the ZF 6HP26 transmission on Jags.
Also affects some Aston Martin, at least one Hyundai, and a few BMW as well.
Issue: sealed for life tranny leaks from composite sump - gasket failure. Cheap nasty fasteners made of cheese have a head size not commensurate with the tiny torx recess. They're also ordinary steel and the casting boss these things screw into are open holes. Lovely little reservoir for all that salty road water. You can guess what happens when attempt is made to remove these pathetic screws. Plain steel screws into aluminium with a dosing of salt water is not sound engineering practise.
Jaguar wanted £700 + to do the job, but much of this is the con trick price of ZF fluid.
I've done mine myself using a 4mm drill and an SKF stud extractor to get the old screws out.
Replace the screws with M6 x 30 stainless socket cap heads and washers. Also fill the top of the hole with waxoyl.
As for the fluid - don't let them BS you that your tranny will fail if anything other than ZF golden elixir is used - it's actually Mercon 5 and you can do a fill for about £30. In fact in some countries Mercon is specified for this box.
Filling presents problems since the fill point is on the side of the box with not much clearance - so no gravity filling here. I spent £12 on a small fuel rated bilge pump at a local Chandlers and it included pipes - best £12 I ever spent.
All in all I've dropped the sump, replaced the gasket, replaced the fasteners with cap head stainless which is what should have been used in the first place, and done a complete refill for about £50. Box runs perfectly.
This was a major issue a while ago with Jag and BMW owners as no one seemed to know what the alternative was for ZF ransom oil, and how to get the old screws out.
So save yourself over £600 - stud extractor, fuel rated small boat bilge pump, M6 x 30 stainless cap heads, Mercon 5 fluid - jobs a good un.
Hopefully this would help anyone with a leaking 6HP26 tranny sump who might be fooled into thinking they have to pay the ransom.
Edited by greenjag03 on Saturday 21st October 21:28
greenjag03 said:
Hi all
Wanted to get this info on the net, hopefully it'll help others with the ZF 6HP26 transmission on Jags.
Also affects some Aston Martin, at least one Hyundai, and a few BMW as well.
Issue: sealed for life tranny leaks from composite sump - gasket failure. Cheap nasty fasteners made of cheese have a head size not commensurate with the tiny torx recess. They're also ordinary steel and the casting boss these things screw into are open holes. Lovely little reservoir for all that salty road water. You can guess what happens when attempt is made to remove these pathetic screws. Plain steel screws into aluminium with a dosing of salt water is not sound engineering practise.
Good info.Wanted to get this info on the net, hopefully it'll help others with the ZF 6HP26 transmission on Jags.
Also affects some Aston Martin, at least one Hyundai, and a few BMW as well.
Issue: sealed for life tranny leaks from composite sump - gasket failure. Cheap nasty fasteners made of cheese have a head size not commensurate with the tiny torx recess. They're also ordinary steel and the casting boss these things screw into are open holes. Lovely little reservoir for all that salty road water. You can guess what happens when attempt is made to remove these pathetic screws. Plain steel screws into aluminium with a dosing of salt water is not sound engineering practise.
Time to pester Jaguar, Aston Martin, Hyundai and BMW or maybe go upstream and take it straight to ZF and
get them to nag their customers ?
Anyone from ZF tech dept reading ?
If your box is a ZF 6HP26 then yes.
In some countries Jaguar actually specifies Ford Mercon 5, or Mercon SP for cars fitted with this box but in europe they don't want you to know that.
Ford owned Jaguar when these trannies were chosen for the S type, and to my knowledge others using a 6HP26 included Aston Martin, Hyundai, BMW, Some Range Rovers - and indeed some Audi's.
It's a serious problem common to all makes - they all eventually leak and use self oxidising crap-co nasty trick fasteners to hold the sump pan on.
There was rumour than some Jag owners were going to Hyundai and getting ZF Lifeguard fluid at non-Jaguar prices.
All to do with making as much profit as possible. Remember these transmissions take about 9 litres of the stuff, and Jaguar quoted me £270 inc vat for a fill. Works out at £30 per litre, daylight robbery.
As it happens £30 - £40 buys you 2 x 5L cans of Mercon 5 or SP if you shop around. No brainer.
Best way for sure is to get under your Audi and see what it says on the transmission sump.
Check this out: audiworld.com and find the following discussion, very interesting indeed - 'Automatic Transmission Fluid (ZFLifegaurd6=Ford Mercon SP)'
Also remember that the filler point probably won't have a lot of room around it. You need a pump to get new fluid in.
In some countries Jaguar actually specifies Ford Mercon 5, or Mercon SP for cars fitted with this box but in europe they don't want you to know that.
Ford owned Jaguar when these trannies were chosen for the S type, and to my knowledge others using a 6HP26 included Aston Martin, Hyundai, BMW, Some Range Rovers - and indeed some Audi's.
It's a serious problem common to all makes - they all eventually leak and use self oxidising crap-co nasty trick fasteners to hold the sump pan on.
There was rumour than some Jag owners were going to Hyundai and getting ZF Lifeguard fluid at non-Jaguar prices.
All to do with making as much profit as possible. Remember these transmissions take about 9 litres of the stuff, and Jaguar quoted me £270 inc vat for a fill. Works out at £30 per litre, daylight robbery.
As it happens £30 - £40 buys you 2 x 5L cans of Mercon 5 or SP if you shop around. No brainer.
Best way for sure is to get under your Audi and see what it says on the transmission sump.
Check this out: audiworld.com and find the following discussion, very interesting indeed - 'Automatic Transmission Fluid (ZFLifegaurd6=Ford Mercon SP)'
Also remember that the filler point probably won't have a lot of room around it. You need a pump to get new fluid in.
dcb said:
Good info.
Time to pester Jaguar, Aston Martin, Hyundai and BMW or maybe go upstream and take it straight to ZF and
get them to nag their customers ?
Anyone from ZF tech dept reading ?
Think its been tried already, excuse was always the same ----"it's a sealed for life unit" Which of course it is'nt, Time to pester Jaguar, Aston Martin, Hyundai and BMW or maybe go upstream and take it straight to ZF and
get them to nag their customers ?
Anyone from ZF tech dept reading ?
Its got drain and filler plugs. But no one got anywhere with these criminals.
Personally I favour either of the following: 1) tech signatory at Jaguar who approved this tranny gets to eat the old screws from mine, or 2)...person at ZF responsible for selecting them in the design gets to eat them.
....But then I'm old school and served my apprenticeship when I was a lad with awareness that mistakes usually involved pain.
For me the PITA was the screws, cheap nasty muck, basically. As fitted to Jaguar, Aston Martin etc :-)
Max_Torque said:
How old was your car?
It's an 03.However, personally I don't see age as a mitigation for bad engineering practice, and it's astounding how this one example has caused so much expense and grief to many.
If you got one of these boxes run your finger over the top of the casting where a fixing screw goes----see how it's open to road water. No wonder the screws corrode, but then they wouldn't if they were stainless.
I do wonder how many cars were either scrapped off or owners got conned into replacement transmissions, when the problem was nothing more than a fluid leak.
My Jag started to kick like a mule on shift changes, reason: low fluid. So you can see how some might be conned as the kick when it's struggling for fluid pressure really is vicious and could be mistaken for a tranny on the way out. Less than honest dealers love this kind of thing.
Other than that to be fair, these boxes are pretty solid, mine's back as smooth as when it was made.
But like I say for me the criminal act was the use of plain steel fasteners with a designed-in salt water reservoir.
Though the box shouldn't leak in the first place, of course.
annodomini2 said:
Mine is the 6HP19A which is a variant of the 6HP26
There is mention on Audi forums about this. Consensus being that your fluid probably is Ford Mercon, or Shell equivalent.Might be wrong but think 6HP denotes six speed, and 19A might be ratios, power loading etc.....but yes yours is a derivative of the series.
Check out forums on audiworld.com, someone took the time to post a very good analysis of the fluids used.
Thing is, manufacturers could easy design and develop a car that could do a million miles and 25 years of use without failure.
Thing is, you wouldn't be able to afford to buy it......
And 03 car is getting on for 15 years old. Cars are designed for 10 years and 150k miles.
Sure, they could have used stainless setscrews, (if we assume for a moment that would have fixed the issue) but it's quite clear there is no real need to do so. The original engineering is perfectly fit for it's purpose / design life.
Thing is, you wouldn't be able to afford to buy it......
And 03 car is getting on for 15 years old. Cars are designed for 10 years and 150k miles.
Sure, they could have used stainless setscrews, (if we assume for a moment that would have fixed the issue) but it's quite clear there is no real need to do so. The original engineering is perfectly fit for it's purpose / design life.
Max_Torque said:
...Cars are designed for 10 years and 150k miles.
Cars are designed to break down as soon as the warranty runs out, otherwise they wouldn't sell any more cars.Sealed for life, is part of the in built failure, i.e. it's sealed for the life of the box, until it explodes.
GreenV8S said:
227bhp said:
Stainless steel is much more liable to cause galvanic corrosion than the steel was.
Just my thought. If it's screwed into aluminium, you might not want to be using stainless fasteners. Passivated non-stainless steel would probably be a better bet.You could always grease the threads and the bolt flange.
Some one told me many years ago & I have done it ever since.
"Just imagine you may be the next person to take it off again".
jjohnson23 said:
Intertesting. Owning dozens of bikes over the years especially ridden in winter I never saw corrosion on stainless fasteners.GreenV8S said:
Just my thought. If it's screwed into aluminium, you might not want to be using stainless fasteners. Passivated non-stainless steel would probably be a better bet.
Depends what the passivation is. If it's Zn then you'd get an instant battery soon as any salt got on it. Cr is what defines Stainless. Cr doesn't rust / oxidise.The original fasteners are just cheap Zn passivated, hence the corrosion.
However the corrosion isn't the main issue. It's the fact that the screws were soft as cheese with a ridiculously small torx diameter. I read somewhere that ZF did increase the torx size after some complaints.
And also the fact that sealed for life isn't, not when the gasket's got a hole in it.
It's just a fine example of what would otherwise be a well designed drivetrain item let down by penny pinching most likely. In every other respect these boxes are damn good.
Edited by greenjag03 on Monday 23 October 19:34
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